1. Field of the Invention
The present invention relates to an optical connection system and to its application to the transmission of video signals.
2. Discussion of Background
Currently, various optical connector technologies are used.
The attached FIG. 1 shows a sectional view along a longitudinal axis OX of a known optical connection system comprising a pump-action optical contact. This technology is especially used for the fibre optic cabling of towns. The connection system comprises two complementary connection elements: a male element, 10, and a female element, 20 complementary to the male element. The male element, 10, comprises, along a longitudinal axis OX, an end-piece 11 having a spring 12. An optical fibre 13 of the same axis is sealed in the centre of the end-piece 11. A metallic part, 14, mechanically retains the assembly. The female element, 20, comprises along a longitudinal axis OX, a central optical fibre, 21, sealed in an end-piece of the same gage as the end-piece of the male element, this end-piece being provided with a part 22, forming a guide, intended for the centreing of the male element when the connection is carried out.
This technology is well mastered and the mounting of the optical contacts requires few tools and remains within the scope of a trained technical person. However, with an optical fibre having a small diameter, the axial and longitudinal alignment of the two fibres, 13, 21, has to be perfect to within a few fractions of micrometers. Likewise, because of the small diameter of the light flux, this type of connector has cleanliness problems as it does not tolerate the least dust particle in the optical path.
The attached FIG. 2 shows a sectional view, along a longitudinal axis OX, of another known optical connection system, comprising a lensed optical contact. This type of connection is especially used for military applications. It is composed of a male element, 30, and of a female element, 40, of which each comprises a central optical fibre, 31, 41, of the same axis. At the end of each optical fibre, 31, 41, and in its continuation, a divergent optical lens 32, 42 is fixed. Each lens 32, 42, causes the light beam arising from the optical fibre to diverge, which enables the problems of optical alignment and of dust in the optical path to be reduced. This technology is less critical for the positioning of the optical fibre and for the cleanliness of the optical contact in relation to the technology of the pump-action contact of FIG. 1; but the positioning of the optical fibre in relation to the optical lens has to be perfect Therefore, the cabling of the optical fibre can only be performed by the supplier of the optical connection element. On the other hand, the polishing and the bonding of the fibre onto the optical lens requires very special and very expensive tools which only the supplier possesses.
Finally, the attached FIG. 3 shows a sectional view of a third known optical connection system comprising a lensed optical contact with a port. Although this technology is similar to that of FIG. 2, each of the male and female connectors furthermore comprises, placed in front of each of the optical lenses, 31, 32, an outer glass port, 33, 34 which protects it. The optical contact is thus impervious and the cleaning easy. However, the positioning of the optical fibre in relation to the optical lens is as tricky as for the optical connection system of FIG. 2.
An optical link not generally being produced in a permanent manner, the optical connection elements are frequently handled, which deteriorates the optical contact intended for the optical link with a complementary optical connection element. Under these conditions, it is necessary to replace the optical connection elements and for this, in the various known optical connector technologies, it is necessary to cut the fibre optic cable. The cabling of the optical fibre on the end-piece of the replacement connector then requires special tools and a skilled work force.